Your Oil Questions answered

Simon,

I was just looking for some advice.

I have just purchased a :-

    Make : BMW

    Model : 330d Sport

    Year : Jan 2004

    Engine Size : 2993

    Engine Type : Diesel (Turbo)

    Gearbox : Automatic

    Mods : None

    Current Mileage : 10k

Firstly what oil would you recommend for this engine ... the best quality.

Secondly, I really want to look after this car/engine and basically hold onto it for at least 5 years and expect to do around 20k miles per year.  In my opinion BMW have stretched the limits now, with services only occurring every 15k.  I therefore plan to do an additional oil change every 7-8k, and imagine this will "look after the engine better".

Do you think this is worthwhile ?

Again what Oil would you recommend ?

I don't want to cut corners as I'm doing additional Oil Changes ... I'm just trying to really look after the engine and ensure trouble free motoring.

Your comments are much appreciated.

 

Cheers.

For those of you that enjoy a good old read, this is heavy going but well worth it!

Building a good oil.

 

It is impossible to make a good 5w-40 or even 10w-40, using only mineral oil. The base oil is so thin, it just evaporates away at the high temperatures found in a powerful engine that is being used seriously. Although there are chemical compounds in there to prevent oil breakdown by oxygen in the atmosphere (oxidation) they cannot adequately protect vulnerable mineral oil at the 130 degC plus sump temperatures found in a hard working turbocharged or re-mapped engine.

 

The answer to this is synthetics. They are built up from simple chemical units, brick by brick so as to speak; to make an architect designed oil with properties to suit the demands of a modern engine.

 

The synthetic myth

 

The word “synthetic” once meant the brick by brick chemical building of a designer oil but the waters were muddied by a court case that took place in the USA some years ago. The outcome was that the right to call heavily modified mineral oil “synthetic” was won. This was the marketing executives dream; the chance to use the word “synthetic” on a can of oil without spending much extra on the contents!

 

Most lower-cost “synthetic” or “semi-synthetic” oils use these “hydrocracked” mineral oils. They do have some advantages, particularly in commercial diesel lubricants but their value in performance engines is marginal.

 

TRUE synthetics are expensive and in basic terms there are three broad catagories, each containing many types and viscocity grades:-

 

PIB’s (Polyisobutanes)

 

These are occasionally used as thickeners in motor oils and gear oils, but their main application is to suppress smoke in two-strokes.

 

The TWO important ones are:

 

ESTERS

 

All jet engines are lubricated with synthetic “esters” and have been for more than 50 years but these expensive fluids only started to appear in petrol engine oils around 20 years ago.

Thanks to their aviation origins, the types suitable for lubricants work well from

 -50 degC to 200 degC, and they have an added benefit. Due to their structure, “ester” molecules are “polar”; they stick to metal surfaces using electrostatic forces. This means that a protective layer is there at all times, even during that crucial start-up period. This helps to protect cams, gears, piston rings and valve train components, where lubrication is “boundary” rather than “hydrodynamic”, i.e. a very thin non pressure-fed film has to hold the surfaces apart.

Even crank bearings benefit at starts, stops, or when extreme shock loads upset the “hydrodynamic” film.

 

Synthetic Hydrocarbons or PAO’s (Poly Alpha Olefins)

 

These are, in effect, very precisely made equivalents to the most desirable mineral oil molecules. As with “esters” they work very well at low temperatures and equally well at high temperatures, if protected by anti-oxidants. The difference is, they are inert and not polar. In fact, on their own they are hopeless “boundary” lubricants, with less load carrying ability than a mineral oil. They depend entirely on the correct chemical enhancements.

 

It is a fact that “PAO’s” work best in combination with “esters”. The “esters” assist load carrying, reduce friction and cut down seal drag and wear, whilst the “PAO’s” act as solvents for the multigrade polymers and a large assortment of special compounds that act as dispersants, detergents, anti-wear and anti-oxidant agents, and foam suppressants.

Both are very good at resisting high-temperature evaporation, and the “esters” in particular will never carbonise in turbo bearings even when provoked by anti-lag systems.

So, in conclusion, Ester gives the best protection and Ester/PAO combinations have great benefits because they work well together. They are more expensive but worth it if you wish to do the best for your engine.

Cheers

Simon

 

edowen wrote: Hi Simon, it's ex-rx8 ed here!   I'm confused - as the 2000 M5 manual definiately says 10-60 oil.... When I spoke to BMW they reccomended Castrol TMS I think - is that 10-60?   I've popped you an email, but I'd be interested to know what I should be topping up with....

 

Ed, sorry you sold your 8!

I believe that the Dealers are putting it in S54 models but this is an odd one as just about all the beemers produced in the last 12 years call for 5w-40 all year round.

Have you spoken to BMW HQ?

Cheers

Simon

 

Russ

I think the best oil for you all year round is a 5w-40 fully synthetic.

Here are a few BMW approved oils that we supply.

Total Quartz 9000 5w-40 (fully syn)

Fuchs Titan Supersyn SL 5w-40 (fully syn)

Silkolene Pro S 5w-40 (ester fully syn)

All these oils are perfectly happy in temperatures ranging from -30 to +30.

E-mail me for prices at sales@opieoils.co.uk

Tech Specs here: http://www.opieoils.co.uk/lubricants.htm

Cheers

Guy

HI Simon:

Once again thank you for the service provided.

But... what about all S50 B30/32 (3.0 and 3.2 Evo) lot? Should we use TwS? or RS (0W40)?

 

Cheers

Francisco

 

I've just got some more Mobil 1 5W-40 to add to my supplies as I was in France on holiday. It is still cheaper than UK retail prices and some trade prices, the best bit is now that it comes in a 5 litre format - still not enough for my engine's capacity, but an extra litre for the same price is good!!

Simon,

I have just acquired an E39 2001 (March) model year M5.  I cannot get any consistent answer about the oil I should use.

Most main dealers say Castrol TWS; but the last Oil Service was done by Dick Lovett in Bristol using Castrol SLX, stating that Castrol TWS was only recommended for M5s up to February 2000.

Munich Legends (Barney) recommends Castrol RS, but isn't this just the retail version of TWS??

Help!

STEPHEN BERRY

Hi again Oilman,

If I understand correctly, you are saying there is a conflict between what BMW (UK) is saying and what the Factory is saying.  The former recommending Castrol TWS 10-60 for all S52 M5's, and the latter recommending Castrol SLX 0-30 for S52 M5's after Feb 2000.

Am I correct.  If so it seems pretty daft to me!!!

 

oilman wrote: I have some clarification on use of 10w-60 for you. BMW 10w-60 Recommendations   BMW has changed their engine-oil recommendation for all M cars equipped with the new S54 engine (E46 M3 coupe and convertible, 2001-on M coupe and M roadster) from the previous BMW High Performance Synthetic 5W-30 engine oil (made by Castrol), to Castrol TWS Motorsport 10W-60 Synthetic Engine Oil (also known as Castrol Formula RS 10W-60. . . the oil is the same, only the name has changed) Presently, BMW recommends Castrol TWS Motorsport 10W-60 for all S54-equipped M-cars as well as all S62-equipped M5s and Z8s produced after 3/00, the factory recommends BMW High Performance Synthetic 5W-30 engine oil. The oil change interval of approximately 15,000 miles or once a year remains unchanged. Cheers Simon

kidsinister wrote: Hi, Oilman Sterling service so far, but here's one: I have a 1982 E21 323i, which I serviced with Castrol's "Oil for older engines" - as the car had done 224k I thought this might be good policy, however, since then the oil warning light has been flickering faintly from startup to well past normal temperature. Have I dropped a clanger using this oil? Have you any specific recommendations for engines of this age/mileage? Many thanks on behalf of all, Alec

Alec,

BMW recomend a 5w-40 for all year round use. However with a car of this mileage you may wish to use something a bit thicker to help with pressure etc. say a 10w-40 What grade are you using at the moment?

If you were to go too thin you would find oil seeping out of seals and other strange places.

I would look at the,

Fuchs Titan Unic Plus 10w-40 fullysyn

or

Fuchs Titan XTR 10w-40 semisyn

Silkolene XTR 10w-40 semisyn

Castrol Performance 10w-40 semisyn

Total Quartz 7000 10w-40 semisyn

E-mail me for prices.

Hope this helps.

Cheers

Simon.

Hi again Simon,

My e-mail tells me that you have replied to my 2 posted queries but there seem to be no replies on the Forum.  How can this be??  Or do you think my questions are already answered elsewhere.

If so I am still none the wiser!!

To summarise, I have a March 2001 E39 5 litre S62 engined M5.  Your clarification on the oil to be used states that BMW (UK presumably) recommend Castrol TWS 10W-60 Motorsport oil, and the Factory (Germany presumably) Castrol 5W-30.  Main dealer workshop computers stipulate the use of TWS for cars built up to Feb 2000, and Dick Lovett say the correct oil is Castrol SLX 0W-30 for vehicles after that date.

So I have a choice of 3 different oils, each apparently the "recommended oil", one of which is significantly different in properties.

I would appreciate a reply, no matter how brief, even if you think I am being unbelievably thick in not understanding the issue.

Kind regards

 

STEPHEN